// JavaScript Document

 function $$(id)  
{  
  return document.getElementById(id);  
}  
 var LoginUI = !!window.LoginUI || {};  

 LoginUI.getViewportWidth = function(){  
    var width=0;  
     if(document.documentElement && document.documentElement.clientWidth){  
     width=document.documentElement.clientWidth;}  

     else if(document.body && document.body.clientWidth){  
    width=document.body.clientWidth;}  

     else if(window.innerWidth){  
    width=window.innerWidth-18;}  
    return width;  
 }  
 LoginUI.getViewportHeight = function() {  
     var height=0;  
     if(window.innerHeight){  
     height=window.innerHeight-18;}  

    else if(document.documentElement&&document.documentElement.clientHeight){  
    height=document.documentElement.clientHeight;}  

     else if(document.body&&document.body.clientHeight){  
     height=document.body.clientHeight;}  
     return height;  
 }  
 LoginUI.getViewportScrollX = function(){  
    var scrollX=0;  

    if(document.documentElement&&document.documentElement.scrollLeft){  
     scrollX=document.documentElement.scrollLeft;}  

    else if(document.body&&document.body.scrollLeft){  
     scrollX=document.body.scrollLeft;}  

    else if(window.pageXOffset){  
     scrollX=window.pageXOffset;}  

    else if(window.scrollX){  
     scrollX=window.scrollX;}  
    return scrollX;  
 }  
 LoginUI.getViewportScrollY=function() {  
     var scrollY=0;  
     if(document.documentElement&&document.documentElement.scrollTop){  
     scrollY=document.documentElement.scrollTop;}  

     else if(document.body&&document.body.scrollTop){  
   	 scrollY=document.body.scrollTop;}  

     else if(window.pageYOffset){  
	 scrollY=window.pageYOffset;}  

     else if(window.scrollY){  
	 scrollY=window.scrollY;}  
     return scrollY;  
 }  

 function TopScrollMsgTip() //返回顶部 
 {  
 	if($$("goTop")){
		var gotop= $$("goTop");
		var t = LoginUI.getViewportHeight()+ LoginUI.getViewportScrollY() - $$("goTop").offsetHeight;  
		if(LoginUI.getViewportScrollY()>90)
		{ 
		  	gotop.style.display="";
		  	gotop.style.top = LoginUI.getViewportHeight()-197+ "px";
			if(typeof document.body.style.maxHeight === "undefined") {
				gotop.style.top = t-50+ "px";
			}
		  	gotop.style.left = LoginUI.getViewportWidth()-130 + "px"; 
		 }
		 else{
			gotop.style.display="none";  
	     }
 	 }
 } 
 function scrollTop()  
 {  
	 TopScrollMsgTip(); 
 }  
 
